xref: /openbmc/linux/security/tomoyo/util.c (revision ebd09753) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * security/tomoyo/util.c
4  *
5  * Copyright (C) 2005-2011  NTT DATA CORPORATION
6  */
7 
8 #include <linux/slab.h>
9 #include <linux/rculist.h>
10 
11 #include "common.h"
12 
13 /* Lock for protecting policy. */
14 DEFINE_MUTEX(tomoyo_policy_lock);
15 
16 /* Has /sbin/init started? */
17 bool tomoyo_policy_loaded;
18 
19 /*
20  * Mapping table from "enum tomoyo_mac_index" to
21  * "enum tomoyo_mac_category_index".
22  */
23 const u8 tomoyo_index2category[TOMOYO_MAX_MAC_INDEX] = {
24 	/* CONFIG::file group */
25 	[TOMOYO_MAC_FILE_EXECUTE]    = TOMOYO_MAC_CATEGORY_FILE,
26 	[TOMOYO_MAC_FILE_OPEN]       = TOMOYO_MAC_CATEGORY_FILE,
27 	[TOMOYO_MAC_FILE_CREATE]     = TOMOYO_MAC_CATEGORY_FILE,
28 	[TOMOYO_MAC_FILE_UNLINK]     = TOMOYO_MAC_CATEGORY_FILE,
29 	[TOMOYO_MAC_FILE_GETATTR]    = TOMOYO_MAC_CATEGORY_FILE,
30 	[TOMOYO_MAC_FILE_MKDIR]      = TOMOYO_MAC_CATEGORY_FILE,
31 	[TOMOYO_MAC_FILE_RMDIR]      = TOMOYO_MAC_CATEGORY_FILE,
32 	[TOMOYO_MAC_FILE_MKFIFO]     = TOMOYO_MAC_CATEGORY_FILE,
33 	[TOMOYO_MAC_FILE_MKSOCK]     = TOMOYO_MAC_CATEGORY_FILE,
34 	[TOMOYO_MAC_FILE_TRUNCATE]   = TOMOYO_MAC_CATEGORY_FILE,
35 	[TOMOYO_MAC_FILE_SYMLINK]    = TOMOYO_MAC_CATEGORY_FILE,
36 	[TOMOYO_MAC_FILE_MKBLOCK]    = TOMOYO_MAC_CATEGORY_FILE,
37 	[TOMOYO_MAC_FILE_MKCHAR]     = TOMOYO_MAC_CATEGORY_FILE,
38 	[TOMOYO_MAC_FILE_LINK]       = TOMOYO_MAC_CATEGORY_FILE,
39 	[TOMOYO_MAC_FILE_RENAME]     = TOMOYO_MAC_CATEGORY_FILE,
40 	[TOMOYO_MAC_FILE_CHMOD]      = TOMOYO_MAC_CATEGORY_FILE,
41 	[TOMOYO_MAC_FILE_CHOWN]      = TOMOYO_MAC_CATEGORY_FILE,
42 	[TOMOYO_MAC_FILE_CHGRP]      = TOMOYO_MAC_CATEGORY_FILE,
43 	[TOMOYO_MAC_FILE_IOCTL]      = TOMOYO_MAC_CATEGORY_FILE,
44 	[TOMOYO_MAC_FILE_CHROOT]     = TOMOYO_MAC_CATEGORY_FILE,
45 	[TOMOYO_MAC_FILE_MOUNT]      = TOMOYO_MAC_CATEGORY_FILE,
46 	[TOMOYO_MAC_FILE_UMOUNT]     = TOMOYO_MAC_CATEGORY_FILE,
47 	[TOMOYO_MAC_FILE_PIVOT_ROOT] = TOMOYO_MAC_CATEGORY_FILE,
48 	/* CONFIG::network group */
49 	[TOMOYO_MAC_NETWORK_INET_STREAM_BIND]       =
50 	TOMOYO_MAC_CATEGORY_NETWORK,
51 	[TOMOYO_MAC_NETWORK_INET_STREAM_LISTEN]     =
52 	TOMOYO_MAC_CATEGORY_NETWORK,
53 	[TOMOYO_MAC_NETWORK_INET_STREAM_CONNECT]    =
54 	TOMOYO_MAC_CATEGORY_NETWORK,
55 	[TOMOYO_MAC_NETWORK_INET_DGRAM_BIND]        =
56 	TOMOYO_MAC_CATEGORY_NETWORK,
57 	[TOMOYO_MAC_NETWORK_INET_DGRAM_SEND]        =
58 	TOMOYO_MAC_CATEGORY_NETWORK,
59 	[TOMOYO_MAC_NETWORK_INET_RAW_BIND]          =
60 	TOMOYO_MAC_CATEGORY_NETWORK,
61 	[TOMOYO_MAC_NETWORK_INET_RAW_SEND]          =
62 	TOMOYO_MAC_CATEGORY_NETWORK,
63 	[TOMOYO_MAC_NETWORK_UNIX_STREAM_BIND]       =
64 	TOMOYO_MAC_CATEGORY_NETWORK,
65 	[TOMOYO_MAC_NETWORK_UNIX_STREAM_LISTEN]     =
66 	TOMOYO_MAC_CATEGORY_NETWORK,
67 	[TOMOYO_MAC_NETWORK_UNIX_STREAM_CONNECT]    =
68 	TOMOYO_MAC_CATEGORY_NETWORK,
69 	[TOMOYO_MAC_NETWORK_UNIX_DGRAM_BIND]        =
70 	TOMOYO_MAC_CATEGORY_NETWORK,
71 	[TOMOYO_MAC_NETWORK_UNIX_DGRAM_SEND]        =
72 	TOMOYO_MAC_CATEGORY_NETWORK,
73 	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_BIND]    =
74 	TOMOYO_MAC_CATEGORY_NETWORK,
75 	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_LISTEN]  =
76 	TOMOYO_MAC_CATEGORY_NETWORK,
77 	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_CONNECT] =
78 	TOMOYO_MAC_CATEGORY_NETWORK,
79 	/* CONFIG::misc group */
80 	[TOMOYO_MAC_ENVIRON]         = TOMOYO_MAC_CATEGORY_MISC,
81 };
82 
83 /**
84  * tomoyo_convert_time - Convert time_t to YYYY/MM/DD hh/mm/ss.
85  *
86  * @time:  Seconds since 1970/01/01 00:00:00.
87  * @stamp: Pointer to "struct tomoyo_time".
88  *
89  * Returns nothing.
90  */
91 void tomoyo_convert_time(time64_t time64, struct tomoyo_time *stamp)
92 {
93 	struct tm tm;
94 	time64_to_tm(time64, 0, &tm);
95 	stamp->sec = tm.tm_sec;
96 	stamp->min = tm.tm_min;
97 	stamp->hour = tm.tm_hour;
98 	stamp->day = tm.tm_mday;
99 	stamp->month = tm.tm_mon + 1;
100 	stamp->year = tm.tm_year + 1900;
101 }
102 
103 /**
104  * tomoyo_permstr - Find permission keywords.
105  *
106  * @string: String representation for permissions in foo/bar/buz format.
107  * @keyword: Keyword to find from @string/
108  *
109  * Returns ture if @keyword was found in @string, false otherwise.
110  *
111  * This function assumes that strncmp(w1, w2, strlen(w1)) != 0 if w1 != w2.
112  */
113 bool tomoyo_permstr(const char *string, const char *keyword)
114 {
115 	const char *cp = strstr(string, keyword);
116 	if (cp)
117 		return cp == string || *(cp - 1) == '/';
118 	return false;
119 }
120 
121 /**
122  * tomoyo_read_token - Read a word from a line.
123  *
124  * @param: Pointer to "struct tomoyo_acl_param".
125  *
126  * Returns a word on success, "" otherwise.
127  *
128  * To allow the caller to skip NULL check, this function returns "" rather than
129  * NULL if there is no more words to read.
130  */
131 char *tomoyo_read_token(struct tomoyo_acl_param *param)
132 {
133 	char *pos = param->data;
134 	char *del = strchr(pos, ' ');
135 	if (del)
136 		*del++ = '\0';
137 	else
138 		del = pos + strlen(pos);
139 	param->data = del;
140 	return pos;
141 }
142 
143 /**
144  * tomoyo_get_domainname - Read a domainname from a line.
145  *
146  * @param: Pointer to "struct tomoyo_acl_param".
147  *
148  * Returns a domainname on success, NULL otherwise.
149  */
150 const struct tomoyo_path_info *tomoyo_get_domainname
151 (struct tomoyo_acl_param *param)
152 {
153 	char *start = param->data;
154 	char *pos = start;
155 	while (*pos) {
156 		if (*pos++ != ' ' || *pos++ == '/')
157 			continue;
158 		pos -= 2;
159 		*pos++ = '\0';
160 		break;
161 	}
162 	param->data = pos;
163 	if (tomoyo_correct_domain(start))
164 		return tomoyo_get_name(start);
165 	return NULL;
166 }
167 
168 /**
169  * tomoyo_parse_ulong - Parse an "unsigned long" value.
170  *
171  * @result: Pointer to "unsigned long".
172  * @str:    Pointer to string to parse.
173  *
174  * Returns one of values in "enum tomoyo_value_type".
175  *
176  * The @src is updated to point the first character after the value
177  * on success.
178  */
179 u8 tomoyo_parse_ulong(unsigned long *result, char **str)
180 {
181 	const char *cp = *str;
182 	char *ep;
183 	int base = 10;
184 	if (*cp == '0') {
185 		char c = *(cp + 1);
186 		if (c == 'x' || c == 'X') {
187 			base = 16;
188 			cp += 2;
189 		} else if (c >= '0' && c <= '7') {
190 			base = 8;
191 			cp++;
192 		}
193 	}
194 	*result = simple_strtoul(cp, &ep, base);
195 	if (cp == ep)
196 		return TOMOYO_VALUE_TYPE_INVALID;
197 	*str = ep;
198 	switch (base) {
199 	case 16:
200 		return TOMOYO_VALUE_TYPE_HEXADECIMAL;
201 	case 8:
202 		return TOMOYO_VALUE_TYPE_OCTAL;
203 	default:
204 		return TOMOYO_VALUE_TYPE_DECIMAL;
205 	}
206 }
207 
208 /**
209  * tomoyo_print_ulong - Print an "unsigned long" value.
210  *
211  * @buffer:     Pointer to buffer.
212  * @buffer_len: Size of @buffer.
213  * @value:      An "unsigned long" value.
214  * @type:       Type of @value.
215  *
216  * Returns nothing.
217  */
218 void tomoyo_print_ulong(char *buffer, const int buffer_len,
219 			const unsigned long value, const u8 type)
220 {
221 	if (type == TOMOYO_VALUE_TYPE_DECIMAL)
222 		snprintf(buffer, buffer_len, "%lu", value);
223 	else if (type == TOMOYO_VALUE_TYPE_OCTAL)
224 		snprintf(buffer, buffer_len, "0%lo", value);
225 	else if (type == TOMOYO_VALUE_TYPE_HEXADECIMAL)
226 		snprintf(buffer, buffer_len, "0x%lX", value);
227 	else
228 		snprintf(buffer, buffer_len, "type(%u)", type);
229 }
230 
231 /**
232  * tomoyo_parse_name_union - Parse a tomoyo_name_union.
233  *
234  * @param: Pointer to "struct tomoyo_acl_param".
235  * @ptr:   Pointer to "struct tomoyo_name_union".
236  *
237  * Returns true on success, false otherwise.
238  */
239 bool tomoyo_parse_name_union(struct tomoyo_acl_param *param,
240 			     struct tomoyo_name_union *ptr)
241 {
242 	char *filename;
243 	if (param->data[0] == '@') {
244 		param->data++;
245 		ptr->group = tomoyo_get_group(param, TOMOYO_PATH_GROUP);
246 		return ptr->group != NULL;
247 	}
248 	filename = tomoyo_read_token(param);
249 	if (!tomoyo_correct_word(filename))
250 		return false;
251 	ptr->filename = tomoyo_get_name(filename);
252 	return ptr->filename != NULL;
253 }
254 
255 /**
256  * tomoyo_parse_number_union - Parse a tomoyo_number_union.
257  *
258  * @param: Pointer to "struct tomoyo_acl_param".
259  * @ptr:   Pointer to "struct tomoyo_number_union".
260  *
261  * Returns true on success, false otherwise.
262  */
263 bool tomoyo_parse_number_union(struct tomoyo_acl_param *param,
264 			       struct tomoyo_number_union *ptr)
265 {
266 	char *data;
267 	u8 type;
268 	unsigned long v;
269 	memset(ptr, 0, sizeof(*ptr));
270 	if (param->data[0] == '@') {
271 		param->data++;
272 		ptr->group = tomoyo_get_group(param, TOMOYO_NUMBER_GROUP);
273 		return ptr->group != NULL;
274 	}
275 	data = tomoyo_read_token(param);
276 	type = tomoyo_parse_ulong(&v, &data);
277 	if (type == TOMOYO_VALUE_TYPE_INVALID)
278 		return false;
279 	ptr->values[0] = v;
280 	ptr->value_type[0] = type;
281 	if (!*data) {
282 		ptr->values[1] = v;
283 		ptr->value_type[1] = type;
284 		return true;
285 	}
286 	if (*data++ != '-')
287 		return false;
288 	type = tomoyo_parse_ulong(&v, &data);
289 	if (type == TOMOYO_VALUE_TYPE_INVALID || *data || ptr->values[0] > v)
290 		return false;
291 	ptr->values[1] = v;
292 	ptr->value_type[1] = type;
293 	return true;
294 }
295 
296 /**
297  * tomoyo_byte_range - Check whether the string is a \ooo style octal value.
298  *
299  * @str: Pointer to the string.
300  *
301  * Returns true if @str is a \ooo style octal value, false otherwise.
302  *
303  * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
304  * This function verifies that \ooo is in valid range.
305  */
306 static inline bool tomoyo_byte_range(const char *str)
307 {
308 	return *str >= '0' && *str++ <= '3' &&
309 		*str >= '0' && *str++ <= '7' &&
310 		*str >= '0' && *str <= '7';
311 }
312 
313 /**
314  * tomoyo_alphabet_char - Check whether the character is an alphabet.
315  *
316  * @c: The character to check.
317  *
318  * Returns true if @c is an alphabet character, false otherwise.
319  */
320 static inline bool tomoyo_alphabet_char(const char c)
321 {
322 	return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
323 }
324 
325 /**
326  * tomoyo_make_byte - Make byte value from three octal characters.
327  *
328  * @c1: The first character.
329  * @c2: The second character.
330  * @c3: The third character.
331  *
332  * Returns byte value.
333  */
334 static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3)
335 {
336 	return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
337 }
338 
339 /**
340  * tomoyo_valid - Check whether the character is a valid char.
341  *
342  * @c: The character to check.
343  *
344  * Returns true if @c is a valid character, false otherwise.
345  */
346 static inline bool tomoyo_valid(const unsigned char c)
347 {
348 	return c > ' ' && c < 127;
349 }
350 
351 /**
352  * tomoyo_invalid - Check whether the character is an invalid char.
353  *
354  * @c: The character to check.
355  *
356  * Returns true if @c is an invalid character, false otherwise.
357  */
358 static inline bool tomoyo_invalid(const unsigned char c)
359 {
360 	return c && (c <= ' ' || c >= 127);
361 }
362 
363 /**
364  * tomoyo_str_starts - Check whether the given string starts with the given keyword.
365  *
366  * @src:  Pointer to pointer to the string.
367  * @find: Pointer to the keyword.
368  *
369  * Returns true if @src starts with @find, false otherwise.
370  *
371  * The @src is updated to point the first character after the @find
372  * if @src starts with @find.
373  */
374 bool tomoyo_str_starts(char **src, const char *find)
375 {
376 	const int len = strlen(find);
377 	char *tmp = *src;
378 
379 	if (strncmp(tmp, find, len))
380 		return false;
381 	tmp += len;
382 	*src = tmp;
383 	return true;
384 }
385 
386 /**
387  * tomoyo_normalize_line - Format string.
388  *
389  * @buffer: The line to normalize.
390  *
391  * Leading and trailing whitespaces are removed.
392  * Multiple whitespaces are packed into single space.
393  *
394  * Returns nothing.
395  */
396 void tomoyo_normalize_line(unsigned char *buffer)
397 {
398 	unsigned char *sp = buffer;
399 	unsigned char *dp = buffer;
400 	bool first = true;
401 
402 	while (tomoyo_invalid(*sp))
403 		sp++;
404 	while (*sp) {
405 		if (!first)
406 			*dp++ = ' ';
407 		first = false;
408 		while (tomoyo_valid(*sp))
409 			*dp++ = *sp++;
410 		while (tomoyo_invalid(*sp))
411 			sp++;
412 	}
413 	*dp = '\0';
414 }
415 
416 /**
417  * tomoyo_correct_word2 - Validate a string.
418  *
419  * @string: The string to check. Maybe non-'\0'-terminated.
420  * @len:    Length of @string.
421  *
422  * Check whether the given string follows the naming rules.
423  * Returns true if @string follows the naming rules, false otherwise.
424  */
425 static bool tomoyo_correct_word2(const char *string, size_t len)
426 {
427 	const char *const start = string;
428 	bool in_repetition = false;
429 	unsigned char c;
430 	unsigned char d;
431 	unsigned char e;
432 	if (!len)
433 		goto out;
434 	while (len--) {
435 		c = *string++;
436 		if (c == '\\') {
437 			if (!len--)
438 				goto out;
439 			c = *string++;
440 			switch (c) {
441 			case '\\':  /* "\\" */
442 				continue;
443 			case '$':   /* "\$" */
444 			case '+':   /* "\+" */
445 			case '?':   /* "\?" */
446 			case '*':   /* "\*" */
447 			case '@':   /* "\@" */
448 			case 'x':   /* "\x" */
449 			case 'X':   /* "\X" */
450 			case 'a':   /* "\a" */
451 			case 'A':   /* "\A" */
452 			case '-':   /* "\-" */
453 				continue;
454 			case '{':   /* "/\{" */
455 				if (string - 3 < start || *(string - 3) != '/')
456 					break;
457 				in_repetition = true;
458 				continue;
459 			case '}':   /* "\}/" */
460 				if (*string != '/')
461 					break;
462 				if (!in_repetition)
463 					break;
464 				in_repetition = false;
465 				continue;
466 			case '0':   /* "\ooo" */
467 			case '1':
468 			case '2':
469 			case '3':
470 				if (!len-- || !len--)
471 					break;
472 				d = *string++;
473 				e = *string++;
474 				if (d < '0' || d > '7' || e < '0' || e > '7')
475 					break;
476 				c = tomoyo_make_byte(c, d, e);
477 				if (c <= ' ' || c >= 127)
478 					continue;
479 			}
480 			goto out;
481 		} else if (in_repetition && c == '/') {
482 			goto out;
483 		} else if (c <= ' ' || c >= 127) {
484 			goto out;
485 		}
486 	}
487 	if (in_repetition)
488 		goto out;
489 	return true;
490  out:
491 	return false;
492 }
493 
494 /**
495  * tomoyo_correct_word - Validate a string.
496  *
497  * @string: The string to check.
498  *
499  * Check whether the given string follows the naming rules.
500  * Returns true if @string follows the naming rules, false otherwise.
501  */
502 bool tomoyo_correct_word(const char *string)
503 {
504 	return tomoyo_correct_word2(string, strlen(string));
505 }
506 
507 /**
508  * tomoyo_correct_path - Validate a pathname.
509  *
510  * @filename: The pathname to check.
511  *
512  * Check whether the given pathname follows the naming rules.
513  * Returns true if @filename follows the naming rules, false otherwise.
514  */
515 bool tomoyo_correct_path(const char *filename)
516 {
517 	return *filename == '/' && tomoyo_correct_word(filename);
518 }
519 
520 /**
521  * tomoyo_correct_domain - Check whether the given domainname follows the naming rules.
522  *
523  * @domainname: The domainname to check.
524  *
525  * Returns true if @domainname follows the naming rules, false otherwise.
526  */
527 bool tomoyo_correct_domain(const unsigned char *domainname)
528 {
529 	if (!domainname || !tomoyo_domain_def(domainname))
530 		return false;
531 	domainname = strchr(domainname, ' ');
532 	if (!domainname++)
533 		return true;
534 	while (1) {
535 		const unsigned char *cp = strchr(domainname, ' ');
536 		if (!cp)
537 			break;
538 		if (*domainname != '/' ||
539 		    !tomoyo_correct_word2(domainname, cp - domainname))
540 			return false;
541 		domainname = cp + 1;
542 	}
543 	return tomoyo_correct_path(domainname);
544 }
545 
546 /**
547  * tomoyo_domain_def - Check whether the given token can be a domainname.
548  *
549  * @buffer: The token to check.
550  *
551  * Returns true if @buffer possibly be a domainname, false otherwise.
552  */
553 bool tomoyo_domain_def(const unsigned char *buffer)
554 {
555 	const unsigned char *cp;
556 	int len;
557 	if (*buffer != '<')
558 		return false;
559 	cp = strchr(buffer, ' ');
560 	if (!cp)
561 		len = strlen(buffer);
562 	else
563 		len = cp - buffer;
564 	if (buffer[len - 1] != '>' ||
565 	    !tomoyo_correct_word2(buffer + 1, len - 2))
566 		return false;
567 	return true;
568 }
569 
570 /**
571  * tomoyo_find_domain - Find a domain by the given name.
572  *
573  * @domainname: The domainname to find.
574  *
575  * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
576  *
577  * Caller holds tomoyo_read_lock().
578  */
579 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
580 {
581 	struct tomoyo_domain_info *domain;
582 	struct tomoyo_path_info name;
583 
584 	name.name = domainname;
585 	tomoyo_fill_path_info(&name);
586 	list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
587 		if (!domain->is_deleted &&
588 		    !tomoyo_pathcmp(&name, domain->domainname))
589 			return domain;
590 	}
591 	return NULL;
592 }
593 
594 /**
595  * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
596  *
597  * @filename: The string to evaluate.
598  *
599  * Returns the initial length without a pattern in @filename.
600  */
601 static int tomoyo_const_part_length(const char *filename)
602 {
603 	char c;
604 	int len = 0;
605 
606 	if (!filename)
607 		return 0;
608 	while ((c = *filename++) != '\0') {
609 		if (c != '\\') {
610 			len++;
611 			continue;
612 		}
613 		c = *filename++;
614 		switch (c) {
615 		case '\\':  /* "\\" */
616 			len += 2;
617 			continue;
618 		case '0':   /* "\ooo" */
619 		case '1':
620 		case '2':
621 		case '3':
622 			c = *filename++;
623 			if (c < '0' || c > '7')
624 				break;
625 			c = *filename++;
626 			if (c < '0' || c > '7')
627 				break;
628 			len += 4;
629 			continue;
630 		}
631 		break;
632 	}
633 	return len;
634 }
635 
636 /**
637  * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
638  *
639  * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
640  *
641  * The caller sets "struct tomoyo_path_info"->name.
642  */
643 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
644 {
645 	const char *name = ptr->name;
646 	const int len = strlen(name);
647 
648 	ptr->const_len = tomoyo_const_part_length(name);
649 	ptr->is_dir = len && (name[len - 1] == '/');
650 	ptr->is_patterned = (ptr->const_len < len);
651 	ptr->hash = full_name_hash(NULL, name, len);
652 }
653 
654 /**
655  * tomoyo_file_matches_pattern2 - Pattern matching without '/' character and "\-" pattern.
656  *
657  * @filename:     The start of string to check.
658  * @filename_end: The end of string to check.
659  * @pattern:      The start of pattern to compare.
660  * @pattern_end:  The end of pattern to compare.
661  *
662  * Returns true if @filename matches @pattern, false otherwise.
663  */
664 static bool tomoyo_file_matches_pattern2(const char *filename,
665 					 const char *filename_end,
666 					 const char *pattern,
667 					 const char *pattern_end)
668 {
669 	while (filename < filename_end && pattern < pattern_end) {
670 		char c;
671 		if (*pattern != '\\') {
672 			if (*filename++ != *pattern++)
673 				return false;
674 			continue;
675 		}
676 		c = *filename;
677 		pattern++;
678 		switch (*pattern) {
679 			int i;
680 			int j;
681 		case '?':
682 			if (c == '/') {
683 				return false;
684 			} else if (c == '\\') {
685 				if (filename[1] == '\\')
686 					filename++;
687 				else if (tomoyo_byte_range(filename + 1))
688 					filename += 3;
689 				else
690 					return false;
691 			}
692 			break;
693 		case '\\':
694 			if (c != '\\')
695 				return false;
696 			if (*++filename != '\\')
697 				return false;
698 			break;
699 		case '+':
700 			if (!isdigit(c))
701 				return false;
702 			break;
703 		case 'x':
704 			if (!isxdigit(c))
705 				return false;
706 			break;
707 		case 'a':
708 			if (!tomoyo_alphabet_char(c))
709 				return false;
710 			break;
711 		case '0':
712 		case '1':
713 		case '2':
714 		case '3':
715 			if (c == '\\' && tomoyo_byte_range(filename + 1)
716 			    && strncmp(filename + 1, pattern, 3) == 0) {
717 				filename += 3;
718 				pattern += 2;
719 				break;
720 			}
721 			return false; /* Not matched. */
722 		case '*':
723 		case '@':
724 			for (i = 0; i <= filename_end - filename; i++) {
725 				if (tomoyo_file_matches_pattern2(
726 						    filename + i, filename_end,
727 						    pattern + 1, pattern_end))
728 					return true;
729 				c = filename[i];
730 				if (c == '.' && *pattern == '@')
731 					break;
732 				if (c != '\\')
733 					continue;
734 				if (filename[i + 1] == '\\')
735 					i++;
736 				else if (tomoyo_byte_range(filename + i + 1))
737 					i += 3;
738 				else
739 					break; /* Bad pattern. */
740 			}
741 			return false; /* Not matched. */
742 		default:
743 			j = 0;
744 			c = *pattern;
745 			if (c == '$') {
746 				while (isdigit(filename[j]))
747 					j++;
748 			} else if (c == 'X') {
749 				while (isxdigit(filename[j]))
750 					j++;
751 			} else if (c == 'A') {
752 				while (tomoyo_alphabet_char(filename[j]))
753 					j++;
754 			}
755 			for (i = 1; i <= j; i++) {
756 				if (tomoyo_file_matches_pattern2(
757 						    filename + i, filename_end,
758 						    pattern + 1, pattern_end))
759 					return true;
760 			}
761 			return false; /* Not matched or bad pattern. */
762 		}
763 		filename++;
764 		pattern++;
765 	}
766 	while (*pattern == '\\' &&
767 	       (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
768 		pattern += 2;
769 	return filename == filename_end && pattern == pattern_end;
770 }
771 
772 /**
773  * tomoyo_file_matches_pattern - Pattern matching without '/' character.
774  *
775  * @filename:     The start of string to check.
776  * @filename_end: The end of string to check.
777  * @pattern:      The start of pattern to compare.
778  * @pattern_end:  The end of pattern to compare.
779  *
780  * Returns true if @filename matches @pattern, false otherwise.
781  */
782 static bool tomoyo_file_matches_pattern(const char *filename,
783 					const char *filename_end,
784 					const char *pattern,
785 					const char *pattern_end)
786 {
787 	const char *pattern_start = pattern;
788 	bool first = true;
789 	bool result;
790 
791 	while (pattern < pattern_end - 1) {
792 		/* Split at "\-" pattern. */
793 		if (*pattern++ != '\\' || *pattern++ != '-')
794 			continue;
795 		result = tomoyo_file_matches_pattern2(filename,
796 						      filename_end,
797 						      pattern_start,
798 						      pattern - 2);
799 		if (first)
800 			result = !result;
801 		if (result)
802 			return false;
803 		first = false;
804 		pattern_start = pattern;
805 	}
806 	result = tomoyo_file_matches_pattern2(filename, filename_end,
807 					      pattern_start, pattern_end);
808 	return first ? result : !result;
809 }
810 
811 /**
812  * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
813  *
814  * @f: The start of string to check.
815  * @p: The start of pattern to compare.
816  *
817  * Returns true if @f matches @p, false otherwise.
818  */
819 static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
820 {
821 	const char *f_delimiter;
822 	const char *p_delimiter;
823 
824 	while (*f && *p) {
825 		f_delimiter = strchr(f, '/');
826 		if (!f_delimiter)
827 			f_delimiter = f + strlen(f);
828 		p_delimiter = strchr(p, '/');
829 		if (!p_delimiter)
830 			p_delimiter = p + strlen(p);
831 		if (*p == '\\' && *(p + 1) == '{')
832 			goto recursive;
833 		if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
834 						 p_delimiter))
835 			return false;
836 		f = f_delimiter;
837 		if (*f)
838 			f++;
839 		p = p_delimiter;
840 		if (*p)
841 			p++;
842 	}
843 	/* Ignore trailing "\*" and "\@" in @pattern. */
844 	while (*p == '\\' &&
845 	       (*(p + 1) == '*' || *(p + 1) == '@'))
846 		p += 2;
847 	return !*f && !*p;
848  recursive:
849 	/*
850 	 * The "\{" pattern is permitted only after '/' character.
851 	 * This guarantees that below "*(p - 1)" is safe.
852 	 * Also, the "\}" pattern is permitted only before '/' character
853 	 * so that "\{" + "\}" pair will not break the "\-" operator.
854 	 */
855 	if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
856 	    *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
857 		return false; /* Bad pattern. */
858 	do {
859 		/* Compare current component with pattern. */
860 		if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
861 						 p_delimiter - 2))
862 			break;
863 		/* Proceed to next component. */
864 		f = f_delimiter;
865 		if (!*f)
866 			break;
867 		f++;
868 		/* Continue comparison. */
869 		if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
870 			return true;
871 		f_delimiter = strchr(f, '/');
872 	} while (f_delimiter);
873 	return false; /* Not matched. */
874 }
875 
876 /**
877  * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
878  *
879  * @filename: The filename to check.
880  * @pattern:  The pattern to compare.
881  *
882  * Returns true if matches, false otherwise.
883  *
884  * The following patterns are available.
885  *   \\     \ itself.
886  *   \ooo   Octal representation of a byte.
887  *   \*     Zero or more repetitions of characters other than '/'.
888  *   \@     Zero or more repetitions of characters other than '/' or '.'.
889  *   \?     1 byte character other than '/'.
890  *   \$     One or more repetitions of decimal digits.
891  *   \+     1 decimal digit.
892  *   \X     One or more repetitions of hexadecimal digits.
893  *   \x     1 hexadecimal digit.
894  *   \A     One or more repetitions of alphabet characters.
895  *   \a     1 alphabet character.
896  *
897  *   \-     Subtraction operator.
898  *
899  *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
900  *               /dir/dir/dir/ ).
901  */
902 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
903 				 const struct tomoyo_path_info *pattern)
904 {
905 	const char *f = filename->name;
906 	const char *p = pattern->name;
907 	const int len = pattern->const_len;
908 
909 	/* If @pattern doesn't contain pattern, I can use strcmp(). */
910 	if (!pattern->is_patterned)
911 		return !tomoyo_pathcmp(filename, pattern);
912 	/* Don't compare directory and non-directory. */
913 	if (filename->is_dir != pattern->is_dir)
914 		return false;
915 	/* Compare the initial length without patterns. */
916 	if (strncmp(f, p, len))
917 		return false;
918 	f += len;
919 	p += len;
920 	return tomoyo_path_matches_pattern2(f, p);
921 }
922 
923 /**
924  * tomoyo_get_exe - Get tomoyo_realpath() of current process.
925  *
926  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
927  *
928  * This function uses kzalloc(), so the caller must call kfree()
929  * if this function didn't return NULL.
930  */
931 const char *tomoyo_get_exe(void)
932 {
933 	struct file *exe_file;
934 	const char *cp;
935 	struct mm_struct *mm = current->mm;
936 
937 	if (!mm)
938 		return NULL;
939 	exe_file = get_mm_exe_file(mm);
940 	if (!exe_file)
941 		return NULL;
942 
943 	cp = tomoyo_realpath_from_path(&exe_file->f_path);
944 	fput(exe_file);
945 	return cp;
946 }
947 
948 /**
949  * tomoyo_get_mode - Get MAC mode.
950  *
951  * @ns:      Pointer to "struct tomoyo_policy_namespace".
952  * @profile: Profile number.
953  * @index:   Index number of functionality.
954  *
955  * Returns mode.
956  */
957 int tomoyo_get_mode(const struct tomoyo_policy_namespace *ns, const u8 profile,
958 		    const u8 index)
959 {
960 	u8 mode;
961 	struct tomoyo_profile *p;
962 
963 	if (!tomoyo_policy_loaded)
964 		return TOMOYO_CONFIG_DISABLED;
965 	p = tomoyo_profile(ns, profile);
966 	mode = p->config[index];
967 	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
968 		mode = p->config[tomoyo_index2category[index]
969 				 + TOMOYO_MAX_MAC_INDEX];
970 	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
971 		mode = p->default_config;
972 	return mode & 3;
973 }
974 
975 /**
976  * tomoyo_init_request_info - Initialize "struct tomoyo_request_info" members.
977  *
978  * @r:      Pointer to "struct tomoyo_request_info" to initialize.
979  * @domain: Pointer to "struct tomoyo_domain_info". NULL for tomoyo_domain().
980  * @index:  Index number of functionality.
981  *
982  * Returns mode.
983  */
984 int tomoyo_init_request_info(struct tomoyo_request_info *r,
985 			     struct tomoyo_domain_info *domain, const u8 index)
986 {
987 	u8 profile;
988 	memset(r, 0, sizeof(*r));
989 	if (!domain)
990 		domain = tomoyo_domain();
991 	r->domain = domain;
992 	profile = domain->profile;
993 	r->profile = profile;
994 	r->type = index;
995 	r->mode = tomoyo_get_mode(domain->ns, profile, index);
996 	return r->mode;
997 }
998 
999 /**
1000  * tomoyo_domain_quota_is_ok - Check for domain's quota.
1001  *
1002  * @r: Pointer to "struct tomoyo_request_info".
1003  *
1004  * Returns true if the domain is not exceeded quota, false otherwise.
1005  *
1006  * Caller holds tomoyo_read_lock().
1007  */
1008 bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
1009 {
1010 	unsigned int count = 0;
1011 	struct tomoyo_domain_info *domain = r->domain;
1012 	struct tomoyo_acl_info *ptr;
1013 
1014 	if (r->mode != TOMOYO_CONFIG_LEARNING)
1015 		return false;
1016 	if (!domain)
1017 		return true;
1018 	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
1019 		u16 perm;
1020 		u8 i;
1021 		if (ptr->is_deleted)
1022 			continue;
1023 		switch (ptr->type) {
1024 		case TOMOYO_TYPE_PATH_ACL:
1025 			perm = container_of(ptr, struct tomoyo_path_acl, head)
1026 				->perm;
1027 			break;
1028 		case TOMOYO_TYPE_PATH2_ACL:
1029 			perm = container_of(ptr, struct tomoyo_path2_acl, head)
1030 				->perm;
1031 			break;
1032 		case TOMOYO_TYPE_PATH_NUMBER_ACL:
1033 			perm = container_of(ptr, struct tomoyo_path_number_acl,
1034 					    head)->perm;
1035 			break;
1036 		case TOMOYO_TYPE_MKDEV_ACL:
1037 			perm = container_of(ptr, struct tomoyo_mkdev_acl,
1038 					    head)->perm;
1039 			break;
1040 		case TOMOYO_TYPE_INET_ACL:
1041 			perm = container_of(ptr, struct tomoyo_inet_acl,
1042 					    head)->perm;
1043 			break;
1044 		case TOMOYO_TYPE_UNIX_ACL:
1045 			perm = container_of(ptr, struct tomoyo_unix_acl,
1046 					    head)->perm;
1047 			break;
1048 		case TOMOYO_TYPE_MANUAL_TASK_ACL:
1049 			perm = 0;
1050 			break;
1051 		default:
1052 			perm = 1;
1053 		}
1054 		for (i = 0; i < 16; i++)
1055 			if (perm & (1 << i))
1056 				count++;
1057 	}
1058 	if (count < tomoyo_profile(domain->ns, domain->profile)->
1059 	    pref[TOMOYO_PREF_MAX_LEARNING_ENTRY])
1060 		return true;
1061 	if (!domain->flags[TOMOYO_DIF_QUOTA_WARNED]) {
1062 		domain->flags[TOMOYO_DIF_QUOTA_WARNED] = true;
1063 		/* r->granted = false; */
1064 		tomoyo_write_log(r, "%s", tomoyo_dif[TOMOYO_DIF_QUOTA_WARNED]);
1065 		printk(KERN_WARNING "WARNING: "
1066 		       "Domain '%s' has too many ACLs to hold. "
1067 		       "Stopped learning mode.\n", domain->domainname->name);
1068 	}
1069 	return false;
1070 }
1071